Goiter

A goiter is an abnormal enlargement of the thyroid gland in the neck. In the US, around 5% of the population have a goiter. This condition is usually benign and non-cancerous, and in most cases, does not require treatment.

What is the thyroid?

The thyroid is a butterfly-shaped gland situated just below the Adam’s apple in the neck. As part of the body’s endocrine system, the thyroid (and parathyroid glands) release two hormones that are responsible for regulating functions such as:

• Growth and development during childhood
• Blood pressure
• Heart rate
• Body temperature
• Metabolism
• Digestion
• Bone maintenance

A goiter refers to any sort of enlargement or growth of the thyroid gland. It can develop as a single nodule on the thyroid, multiple nodules, or as a general enlargement.

Goiter Symptoms

In many cases, a goiter will be small enough to not cause any symptoms. In fact, many people don’t even realize they have a goiter and it’s only detected as a coincidental finding during a medical exam for another issue.

If the goiter grows large enough, there may be a noticeable swelling in the neck. While the goiter itself is painless, there may be symptoms associated with the swelling as it presses on surrounding structures in the neck, such as:

• Difficulty swallowing
• Difficulty breathing, especially when lying down
• A sensation of fullness or pressure around the neck
• Coughing
• Voice changes and hoarseness

Because a goiter has the potential to affect the production of thyroid hormones, it can also be associated with a number of other signs and symptoms specific to whether thyroid hormone levels are increased or decreased.

In the case of hyperthyroidism (elevated thyroid hormones), symptoms include:

• Increased blood pressure and heart rate
• Unintentional weight loss
• Excessive sweating
• Irritability and nervousness
• Increased appetite
• Menstrual disturbances in women
• Muscle weakness and tremors

In the case of hypothyroidism (reduced thyroid hormones), symptoms include:

• Fatigue
• Dry skin
• Constipation
• Increased sensitivity to cold
• Difficulties with concentration and memory

Goiter Causes

At a fundamental level, a goiter is reaction of the thyroid’s cells to any disruption to thyroid hormone production. If the pituitary gland senses low thyroid hormone levels, it produces more of its own hormone, which stimulates the thyroid to grow, resulting in a goiter.

This can be due to a number of conditions, such as:

• Iodine deficiency: although this is the most common cause of goiter worldwide, in the US, goiter from iodine deficiency is rare due to the availability of iodized table salt.
• Hashimoto’s disease: an autoimmune disorder, Hashimoto’s thyroiditis is a more common cause of goiter in the US. During this condition, the body’s own immune system mistakenly attacks and damages the thyroid gland.
• Graves’ disease: this is another autoimmune disease often responsible for the development of a goiter. In Graves’, the body’s immune system produces a protein that mimics the hormone produced by the pituitary gland, stimulating abnormal thyroid growth and overactivity.
• Thyroid nodules: the cause of these collections of overgrowths of thyroid cells is unclear. There may be contribution from a number of factors, such as genetics, diet, lifestyle choices, and the environment.

Other conditions include hormonal changes from pregnancy or inflammation of the thyroid causing hyper- or hypothyroidism.

Thyroid cancer is a possible but rare cause of goiter. In the US, only about 5% of thyroid nodules are cancerous.

Though any person of any age can develop a goiter, it’s most commonly found in women and those over the age of 40. Other risk factors for goiter include:

• Periods of hormonal disruption, including pregnancy and menopause
• Having a family history of goiter or other thyroid disorders
• Certain medications, such as amiodarone or lithium
• Exposure to radiation therapy in the neck or chest area
• Low iodine in the diet

Goiter Diagnosis and Treatment

As many goiters are small and asymptomatic, they may only be noticed as a coincidental finding during a routine medical check-up or during an imaging test for a different condition.

A doctor may be able to feel a goiter with a physical exam of the neck around the area of the thyroid. Additional tests can confirm the presence of a goiter and how it may be affecting thyroid function, such as:

• Blood tests: to measure the levels of thyroid-related hormones, including those produced by the pituitary gland and the thyroid itself; to measure antibodies that may indicate an autoimmune condition such as Hashimoto’s or Graves’.
• Ultrasound: allows the doctor to visualize nodules and the size of the thyroid.
• Radioactive iodine uptake: a small amount of radioactive iodine is swallowed either as a liquid or in a capsule. Once the iodine has had time to be taken up by the thyroid gland, a scan is performed over the thyroid to detect how much iodine has been absorbed, giving an indication of thyroid function.
• Fine needle aspiration biopsy: involves using ultrasound to guide a thin needle in removing a sample of tissue or fluid from any thyroid nodules for testing.

If the goiter is not causing any concerns, it may simply be monitored with regular exams by a doctor. If there are issues with the size of the goiter or its impact on thyroid function, treatment depends on the symptoms and underlying cause.

Treatment options for goiter include:

• Medications: to regulate thyroid hormones, whether to increase or reduce hormone production. Medications are used to manage Hashimoto’s thyroiditis. Rebalancing thyroid hormone levels can help to decrease the size of the goiter.
• Surgery: a total or partial removal of the thyroid gland (thyroidectomy) may be necessary if symptoms are severe, such as difficulty with swallowing or breathing, or if nodules on the thyroid are causing overactivity or are found to be cancerous. Depending on how much of the thyroid is removed, long-term medications may be necessary to replace the thyroid hormones.
• Radiofrequency ablation: radio waves are applied to thyroid nodules using a thin needle guided by ultrasound. The heat from the electrical current destroys cells in the nodules, causing them to shrink. Radiofrequency ablation is only appropriate for non-cancerous nodules.
• Radioactive iodine therapy: this is used for situations of hyperthyroidism, including Graves’ disease, and some types of thyroid cancer. Similar to the radioactive iodine test, a solution or pill of radioactive iodine is taken by mouth, then is absorbed into the thyroid where the cells are destroyed by the radiation. Because the iodine is preferentially collected by the thyroid, other parts of the body are less affected. The dose of radiation in radioactive iodine therapy is much higher than that used in the scan.

In the US, endocrinologists and ENT (ear, nose, throat) specialists are trained in the treatment of goiter and other thyroid disorders.